Neuroscience and intimate relationships
Throughout history, predominately, philosophy and religion have speculated the most into the phenomena of love and intimate relationships. In the last century, the science of psychology has written a great deal on the subject. Recently, however, the sciences of evolutionary psychology, evolutionary biology, anthropology, neuroscience, and biology have begun to take center stage in discussion as to the nature and function of love. The general consensus supposes that the phenomenon and process of love is subject to the laws of science just as is anything in the universe. Recent writings have focused on making a connection between love and evolution. Overview Biological models of sex tend to see it as a mammalian drive, just like hunger or thirst. Current psychological theories view love from a more social and cultural perspective. There are probably elements of truth in both views — certainly love is influenced by hormones (such as oxytocin) and pheromones, and how people think and behave in love is influenced by one’s conceptions of love. Hence, from time immemorial, science, from naturalistic poetry to MRI neurochemistry, has since debated over the nature of love. Biological sciences such as evolutionary psychology, evolutionary biology, anthropology and neuroscience have begun to explore the nature and function of love. Specific chemical substances such as oxytocin are studied in the context of their roles in producing human experiences and behaviors that are associated with love. Evolutionary psychology From the perspective of evolutionary psychology the experiences and behaviors associated with love can be investigated in terms of how they have been shaped by human evolution."Evolutionary psychology: the emperor's new paradigm" by D. J. Buller in Trends Cogn. Sci. (2005) Volume 9 pages 277-283. For example, it has been suggested that human language has been selected during evolution as a type of "mating signal" that allows potential mates to judge reproductive fitness.The Mating Mind: How Sexual Choice Shaped the Evolution of Human Nature by Geoffrey F. Miller in Psycoloquy (2001) 12,#8. Miller described evolutionary psychology as a starting place for further research: "Cognitive neuroscience could try to localize courtship adaptations in the brain. Most importantly, we need much better observations concerning real-life human courtship, including the measurable aspects of courtship that influence mate choice, the reproductive (or at least sexual) consequences of individual variation in those aspects, and the social-cognitive and emotional mechanisms of falling in love." Since Darwin's time there have been similar speculations about the evolution of human interest in music also as a potential signaling system for attracting and judging the fitness of potential mates.Evolution of human music through sexual selection by G. F. Miller in N. L. Wallin, B. Merker, & S. Brown (Eds.), The origins of music, MIT Press, (2000). pp. 329-360. It has been suggested that the human capacity to experience love has been evolved as a signal to potential mates that the partner will be a good parent and be likely to help pass genes to future generations.Sexual selection and mate choice in evolutionary psychology (PDF) by C. Haufe in Biology and Philosophy Neurochemistry Studies in neuroscience have involved chemicals that are present in the brain and might be involved when people experience love. These chemicals include: nerve growth factorwww.ncbi.nlm.nih.gov/pubmed/16289361, testosterone, estrogen, dopamine, norepinephrine, serotonin, oxytocin, and vasopressin."The neurobiology of love" by S. Zeki in FEBS Lett. (2007) Volume 581 pages 2575-2579. PMID 17531984 Adequate brain levels of testosterone seem important for both human male and female sexual behavior.The endocrinology of sexual arousal by J. Bancroft in Journal of Endocrinology (2005) Volume 186 pages 411-427. Dopamine, norepinephrine, and serotonin are more commonly found during the attraction phase of a relationship. Oxytocin and vasopressin seemed to be more closely linked to long term bonding and relationships characterized by strong attachments. The conventional view in biology is that there are two major drives in love — sexual attraction and attachment. In the February 2006 issue of National Geographic, Lauren Slater's cover page article "Love: The Chemical Reaction" Attachment between adults is presumed to work on the same principles that lead an infant to become attached to his or her mother or father. The chemicals triggered that are responsible for passionate love and long-term attachment love seem to be more particular to the activities in which both persons participate rather than to the nature of the specific people involved. Helen Fisher, a leading expert in the topic of love, also adds lust to the experience of love. Lust exposes people to others, and is the initial passionate sexual desire that promotes mating, and involves the increased release of chemicals such as testosterone and estrogen. These effects rarely last more than a few weeks or months. Serotonin Chemically, the serotonin effects of being in love have a similar chemical appearance to obsessive-compulsive disorder; which could explain why a person in love cannot think of anyone else."Aphrodisiacs past and present: a historical review" by P. Sandroni in Clin. Auton. Res. (2001) Volume 11 pages 303-307 Abstract For this reason some assert that taking SSRIs and other antidepressants, which treat OCD, impede one's ability to fall in love. In one particular case anthropologist Helen Fisher noted: Oxytocin The long-term attachment felt after the initial "in love" passionate phase of the relationship ends is related to oxytocin, a chemical released after orgasm.Carmichael MS, Humbert R, Dixen J, Palmisano G, Greenleaf W, Davidson JM. (1987) Plasma oxytocin increases in the human sexual response. J Clin Endocrinol Metab 64:27-31 PMID 3782434 Moreover, novelty triggers attraction. Even working out for several minutes can make one more attracted to other people on account of increased heart rate and other physiological responses. Nerve growth factor In 2005, Italian scientists at Pavia University found that a protein molecule known as the nerve growth factor (NGF) has high levels when people first fall in love, but these return to previous levels after one year. Specifically, four neurotrophin levels (NGF, BDNF, NT-3, and NT-4) of 58 subjects who had recently fallen in love were compared with levels in two control groups who were either single or already engaged in a long-term relationship. The results showed that NGF levels were significantly higher in the subjects in love than as compared to either of the control groups.Emanuele, E.; Polliti, P.; Bianchi, M.; Minoretti, P.; Bertona, M.; & Geroldi, D. (2005). “Raised plasma nerve growth factor levels associated with early-stage romantic love.” Abstract. Psychoneuroendocrinology, Sept. 05. Role of the limbic system In A General Theory of Love, three professors of psychiatry from UCSF provide an overview of the scientific theories and findings relating to the role of the limbic system in love, attachment and social bonding. They advance the hypothesis that our nervous systems are not self-contained, but rather demonstrably attuned to those around us and those with whom we are most close. This empathy, which they call limbic resonance, is a capacity which we share, along with the anatomical characteristics of the limbic areas of the brain, with all other mammals. Their work builds on previous studies of the importance of physical contact and affection in social and cognitive development, such as the experiments conducted by Harry Harlow on rhesus monkeys, which first established the biological consequences of isolation. Brain imaging Brain scanning techniques such as magnetic resonance imaging have been used to investigate brain regions that seem to be involved in producing the human experience of love.Reward, Motivation, and Emotion Systems Associated With Early-Stage Intense Romantic Love by Arthur Aron1, Helen Fisher, Debra J. Mashek, Greg Strong, Haifang Li and Lucy L. Brown in Journal of Neurophysiology (2005) Volume 94, pages 327-337. See also *Biological Attraction *Love *Love (cultural views) *Love (religious views) *Love sickness *Love-shy References External links *The Science of Love * The Nature of Love (1958) - Harry Harlow, American Psychologist, 13, 573-685 * Harry Harlow - A Science Odyssey: People and Experiments * The science of romance: Brains have a love circuit AP }} Category:Interpersonal chemistry See also *Attraction *Love *Love (cultural views) *Love (religious views) *Neuroscience of animal pair bonding References # Helen Fisher. Why We Love: the Nature and Chemistry of Romantic Love External links *The Science of Love *The Thermodynamics of Love *Thermodynamics, Psychology, Chemistry, and Love *Chemistry - a Central Pillar of Human Culture Harry Harlow * Harlow: Monkey Love Experiments - Adoption History * The Nature of Love (1958) - Harry Harlow, American Psychologist, 13, 573-685 * Harry Harlow - A Science Odyssey: People and Experiments Category:Relationships Category:Affection